Hiccup / stutter / misfire / intake backfire

[giarcg]

Typically those are a simple 3¢ resistor to lower the o2 signal voltage and trick the ECM into making the entire fuel map an untested and unregulated amount richer.

I'm glad your impression is that it worked for you, but I would highly recommend not doing that.

It's far more than a three cent resistor and far more than an impression. Educate yourself, research its use on Harleys and BMWs. Evidence of its effectiveness is shown in the AFV values responding to the level of enrichment selected. The engine running smoother with an increase in responsivenes is the ultimate test as far as I'm concerned. Regulation is achieved through it's adjustability.

The OP (and others) should not discount this as a possible solution... I'm glad I didn't.

 

[giarcg]

Perform intake leakage test.

Worth doing but my experience was that testing with propane/carb cleaner was not bulletproof. Mine tested good but changing the seals anyway made a big improvement. I think seal leakage can vary depending on heat and vibration levels changing while riding. Not necessarily the same levels seen at idle in the shop. Going forward I'll be changing them as routine maintenance every three years or so...

 

[user_deleted]

giarcg: THAT is precisely the device i was referring to earlier. and i remember the source now. late summer of 2014 purchased some lightly used and new XB parts from a former buell owner in northeast PA via craigslist. in the pile was this nightrider.com tuning device. the guy had planned on installing it on his XB12 but never did. was NIB and tempting to me as it received glowing endorsements via several net sites. as previously mentioned was both irritatated and frustrated with the rideability issues of my late 2009 Uly to the point of just unloading it and moving on. note that i did NOT "tune" my stock ecm due to lack of software and knowledge. the installation of THAT device on THAT particular XB was a remarkable success. the ease of installation and rideability improvement along with resolution of nagging problems was outstanding. i will mention that the CEL would activate at every cold start-up but as soon as system went into closed-loop CEL extinguished. no historic fault codes ever recorded. and that was my experience with said device.

 

[giarcg]

giarcg: THAT is precisely the device i was referring to earlier.

I researched this gizmo quite a bit before buying for two of my BMW oil heads and there is a ton of excellent info from informed people in the BMW forums. Its referred to as a lambda shift device and to me the theory makes perfect sense. Bottom line is it works, it gets the mixture off the lean side and engines respond. I only wish I thought of trying it sooner and not having to put up with a year of frustration.

 

[moose09876]

Ok, seriously. I've done 4 logs and 3 VEAnalyze for new maps and every time it makes it worse. Every time, it wants to remove fuel from the area where it's having issues.

 

[njloco]

Two questions from someone who is totally ignorant when it comes to this stuff.
1- how does one know which one to buy ?
2- from what I read, all this does is change the resistance signal to the ECM ?
If this later question is true, why not just figure out what the resistance amount is and put in a slightly variable resistor in that range ? Like I said I am totally ignorant about this stuff but, this is what we did on our diesel forum for the EGR along with a blocker plate.

 

[gdisaac07]

Ok, seriously. I've done 4 logs and 3 VEAnalyze for new maps and every time it makes it worse. Every time, it wants to remove fuel from the area where it's having issues.

1. What is your AFV?
2. To summarize, when the bike idles or is at low speed when cold, then you have runability problems?
3. What kind of fuel are you using?
4. Which ECM version do you have? (Is your bike DDFI3?)

Let me know! My problems with my bike have led me through a lot of troubleshooting that may be helpful to you.

 

[giarcg]

njloco - Not clear to me if you're inquiring about the AF-Xied or not. If so I suggest you spend some time researching it and read what people far more knowledgeable than I have to say about it.

Here is a place to start: http://advrider.com/index.php?threa...o2-sensor-project-and-af-xied-for-bmw.749080/

 

[moose09876]

1. What is your AFV?
   100
2. To summarize, when the bike idles or is at low speed when cold, then you have runability problems?
   The misfire / stutter happens between 1500 and 3000 rpm 98% of the time. Once it hits 3k, runs perfectly.
3. What kind of fuel are you using?
   always 93 octane
4. Which ECM version do you have? (Is your bike DDFI3?)
   BUEGB - DDFI2

Thanks

 

[Cooter]

Giarcg: Like I said, I'm glad it worked for you, and I'm sure it could work for others with your exact rideability issue. Without proper diagnosis, you were lucky that your bike needed to be globally enriched to make your rideability better. Congrats:up:

But I caution you, there are way too many variables in different motorcycles and tuning to assume its a magic fix for everyone:upset:. "Lambda shift" is salesman speak for resistor. It uses a resistor to lower the voltage signal from the O2 sensor to the ECM, thereby 'shifting the Lambda' the ECM sees. Adjustable resistor or not, thats what it is. If your "gizmo" [your words] only hooks up to the O2, thats all it can be. No magic stick in there Harry P. You can do the same thing your gizmo does a bit more precisely by changing the O2 values with ECMDroid, ECMSpy, or TunerPro, but I wouldn't recommend that for Moose either for the same reasons.

That's why I would hesitate blanket recommending you gizmo to everyone who has any kind of rideability issue.

Moose: We don't even know if you have a tuning issue. We know you have a rideability issue. Sure it could be caused by tuning, but the ECM won't change tuning without a reason (and you have the same exact issue with both ECM's...) The ECM uses sensors to dictate it's output. It's much more likely there is a sensor issue causing the ECM to receive incorrect info, or a mechanical issue such as intake leak (common on a Buell), dirty injectors, weak fuel pump, etc.

It's frustrating to have a bike not run well, and tuning can be tricky. So lets try to diagnose your bike to fix it. Otherwise you are just shooting cash into the dark to see what happens. Maybe you get lucky? Heck, maybe you need to globally enrich the map just like that magic gizmo does BUT... your much richer 'race ECM' doesn't solve your rideability issue so I highly doubt thats what you need? If you still want to guess and see if that thing works of you, maybe he'll ship it to you to try out?

Before you send your datalog into VE Analizer, take a close look at it. What is the ECM seeing when it runs poorly? What does your O2 read in closed loop then? any sensors with erratic signals? CPS? TPS? You've got the tools already, lets use them

 

[moose09876]

Closed / open loop makes no difference. 02 fluctuates between .1 and .8 when in closed loop, looks normal. No crazy signals that I can see, hard to track it down because when it's running poorly since it might be a constant 3-4 times per second or once every couple seconds. I've looked at logs when I KNOW it was doing it constantly, then I got on the gas and it went away and seen nothing outstanding in the logs. TPS is giving accurate readings, haven't done anything with CPS.

 

[giarcg]

Cooter... never said or implied it was a"magic fix for everyone", I refered to it as a possible solution worth considering. Obviously if the engine has a significant mechanical condition .... including an intake leak such as mine did, it would have to be corrected. There are two experienced people in this thread that have had success in dealing with less than optimum running due to what I think is EPA induced lean mixture programming. Both used the AF-Xied.

There is plenty of info out there for anybody that cares to look to determine if it would be something they want to persue.

 

[giarcg]

Cooter - I'm hestitant to bring this up but I'll add this since you are focused on the variable resistor concept. Obviously the AF-Xied is altering the signal from the O2 sensor... I don't pretend to know exactly what its doing to it but having spoken with its designer I know its more than just a simple variable resistor.

I proved this to myself unintentionaly by first trying the Vied unit from the same manufacturer. From its appearance alone I would call it a simple variable resistor . Results were not good, inconsistent running and tripping of the CEL. I removed it not long after trying it. Months later, based on my experience with my BMWs, I tried the AF-Xied on the Uly and achieved the great results previously mentioned.

 

[Cooter]

Moose, the thing about it only coughing when it's pretty cold engine temp or ambient below 65* would seem its an open-loop problem, where the ECM is running a set program and not even referencing the O2 sensor. Confirmed by you saying you tried a heated O2 as well with no change.

Can you see that in the datalog? If you can confirm the ECM is in open loop when it's acting poorly perhaps the solution lies with simply enriching the cold-start open loop settings and not touching the regular fuel map or VE analyzing anything?

Try comparing the stock ECM and the 'race' ECM open loop settings. I don't know, but its very possible they are the same, (because why wouldn't they be?) which would explain the same issue with both ECM's installed.

"Hiccup / stutter / misfire / intake backfire" are usually signs it's lean or timing problems. Since it runs great when warm, we can make timing a secondary diagnosis.

Lean could be tuning, or could be caused by extra air/not enough fuel. When it's cold like that and needs a bunch of extra fuel, it's taxing things like injectors, fuel pump, etc. It's possible to 'tune out' a small issue but that could be masking a problem that will get worse.

So when you're in the mood, the list to check is:

Compare open loop settings on both ECM's. If you want to play with it, enrichen it a bunch (like 15% or so) and see how that does.

Triple check for an intake leak, I know, I know, humor me....

Pull the injectors and see how they spray (tankful of seafoam doesn't count ahaha)

Check fuel pressure.

Since it's bee apart, check airhorn gasket on base plate, and grounds (again) can't have too many grounds!!

And surface energy. Make sure you have lots and lots of surface energy:black_eyed:

 

[gdisaac07]

The misfire / stutter happens between 1500 and 3000 rpm 98% of the time. Once it hits 3k, runs perfectly.

I'm sorry if some of this is a bit basic, but a lot of the time the basic stuff is the most important!

And only when cold? Or when cold and warm?

If it's only when the engine is cold, then you have a problem that is confined to only Open Loop operation. If you have a stock map, which is supposed to work with a bike that is IN NEARLY PERFECT MECHANICAL FUNCTION. If the stock map is not functioning, then you have three roads to go down.

1. Fuel
2. Air
3. Electronics

We're going to assume that your electronics are fine for now. So that leaves Fuel and Air.

FUEL

Fuel has to both get there, and get there at the right time.

Fuel getting there basically means that there is adequate fuel pressure AT THE FUEL RAIL. This can be tested for easily. There is a procedure to test this. It is listed in the manual (http://buellmods.com/content/downloads/manuals/xbxulysses/2007_ulysses_manual.pdf) on page 381. Ensure that your fuel pressure is maintained at idle, low revs, and high revs, both when hot and cold.

• If the fuel pressure is low at idle, then you have a fuel pump/regulator/filter issue (I doubt this as AFV is normal)
• If the fuel pressure is fine at idle but dips when initially getting on the throttle, then normal again, you can have a few problems (kinked/hardened fuel supply hose, kinked/deformed fuel vent hose, wiring issue to fuel pump, clogged fuel filter, bad fuel regulator). If you do the same test with the gas tank cover off and this is normal, then it's probably a kinked fuel supply hose

The electronics (fuel map, etc) control fuel getting there at the right time. We'll ignore the fuel mapping, but the injectors are possible causes. If the pressure test is good, then the best thing I can recommend there is removing the injectors and sending them out to be tested/repaired. This guy is cheap and will tell you if there are any problems with the injectors (electrical or physical) and will clean them and send them back in factory condition. $16.25/injector, plus like $8 for shipping. http://www.hurstinjectorservice.com/

Otherwise, there could be a problem with the fuel in the tank/particulate/growth.

AIR

The other part of combustion is enough air. Intake test is good. It sounds like everyone else has pretty substantially covered the air issue, and with the exception of the seals, this isn't usually a problem.

I've gotta head out rn, but I'll tackle more of this later. But definitely do the fuel pressure test immediately and see if you can find anything out.

 

[moose09876]

Here are 2 logs that I captured today. When cruising above 3k rpm, no issues. there's almost always a stutter at 2700ish rpm.

https://drive.google.com/file/d/13GTGyO83lSW-cZXb0BIS6HSS2NI9XOkX/view?usp=sharing
https://drive.google.com/file/d/1NiqEkzSfBtWe-YJ7SNm8FQt0dTbor0VW/view?usp=sharing

 

[moose09876]

Bringing this back from the dead since I've gotten nowhere and it's riding time again. Every time I do a log and run the VEanalyzer, it tries to lean out the area where I'm getting the misfire. Checked the plugs yet again, and if anything, it's running lean. Also has issues starting. After a TPS reset, it will start and idle fine when warm, but when it's cold, it idles way too low and dies.

 

[lowkey]

Bringing this back from the dead since I've gotten nowhere and it's riding time again. Every time I do a log and run the VEanalyzer, it tries to lean out the area where I'm getting the misfire. Checked the plugs yet again, and if anything, it's running lean. Also has issues starting. After a TPS reset, it will start and idle fine when warm, but when it's cold, it idles way too low and dies.

(in response for the first bold section) Are you setting up VEanalyzer correctly? Filtering out the log with engine temp below 160-180 degrees Celsius?(in response to the second bold section) What are ambient temps? Were talking fully ambient starting engine temps correct? Scale back cold start enrichment percentages i.e. 160% make it 150% and try again, scale back % up the temp scale until the 180 degree Celsius temp (should be 100%). For instance I'm currently tuning with a WB and still have stock cold start enrichment values on a completely cold engine in 85-90 degree ambient temps, when I initially start the bike the AFR is 11.8-12.0 whereas once the CLT is 180 I idle at AFR 14.7, You can see cold start is meant to act as a digital choke but values are overly rich and for to long up the temp scale IMO.

To get idle perfect all you have to do is bring CLT to 180 degrees so no more enrichment % is applied and view EGO % in live data, if below 100% remove fuel to that cell (TPS/RPM cross cell/cells), If above 100% add fuel to that cell/cells. It's going to fluctuate around 100 even when perfect because of the NB sensor characteristics but get it as close as possible.

EDIT:

Back to setting up MLV properly, you should reset the program and start from scratch for it's settings. First make sure you change Y-axis by typing in "Load", next make sure O2 is set to NB in the drop down and lambda is the first option (should read "default" IIRC). Vehicle/ECM I leave on default and not "Buell". Now you move onto the right of the graphing by loading the .msq that you had for the log you are attempting to analyze. Make sure the top table is the "VEbins2" if you are logging with stock NB rear sensor. Make sure your logs have the "engine byte" data or this could be your problem, with this data VEanalyzer knows to filter acceleration enrichment and declaration fuel % reduction when analyzing the log, if these are not filtered you will never get the fuel maps right. You will know if the log has this data from the signal box across the bottom of the software labeled "engine" as well as a row of boxes under and to the right of the graph/VE analyze selections (look for accel/decel that light and show "yes" sometimes while playing the log.
If all that is correct it is time to select VE analyze so the window comes up. Click advanced settings button and make sure the engine temperature is set to 180 (some use 160 but 180 is 0% additional fuel enrichment), Make sure your AFRbin table looks correct (you can always change this to your liking). Set changes to med or hard depending how far along in logs you've done and see how that works for you.

Also you have closed loop idle checked in whatever software you use to communicate with the motorcycle as well as closed loop enabled correct?

 

[moose09876]

VE analyzer - Since it's cold out, the bike doesn't get over 160C. Ambient has been 40-65F when experiencing the original issue with stutter at 2-3k rpm. I'll try leaning out the cold start enrichment tomorrow when I mess with it. Edit: set it to 140 and also 125. Same result. The front cyl is not firing at low RPM's. If I give it throttle, it will run poorly. Since it won't run, I'm at a loss.

Idle - when I could get the bike up to 180C, I could adjust the idle properly and reset TPS. Now it won't start/run long enough to get it back up to temp.

At this point I'm more than willing to pay somebody to get it running properly, as everything I do seems to make it worse. Anybody know of someone in proximity to Indianapolis that is familiar with Buells?

 

[lowkey]

VE analyzer - Since it's cold out, the bike doesn't get over 160C. Ambient has been 40-65F when experiencing the original issue with stutter at 2-3k rpm. I'll try leaning out the cold start enrichment tomorrow when I mess with it. Edit: set it to 140 and also 125. Same result. The front cyl is not firing at low RPM's. If I give it throttle, it will run poorly. Since it won't run, I'm at a loss.

Obviously VE analyzer will report the cells as being overly rich from 14.7 with enrichment % being added... will never work for you using the software this way. Also these are two separate issues, not the same.

Idle - when I could get the bike up to 180C, I could adjust the idle properly and reset TPS. Now it won't start/run long enough to get it back up to temp.

This is NOT what I'm talking about that procedure is simply setting the TPS, I'm talking about adjusting the fuel cell table value in relation to TP/RPM for 14.7 and not relying on EGO to adjust for the incorrect value for you.

At this point I'm more than willing to pay somebody to get it running properly.

Forgive me as I didn't read the whole thread and only you last post, I will go from page 1 through to the end. Do you have a video of it idling/running in its current state? PM me your email and we can talk further, I have an idea of the possible cause of your issue just from the more info provided in this post. You have the BUEIB ECMID I presume?